Though primarily spending their lives in fields, agricultural vehicles still need to transit on public roads, and as such, on-road performance is a key consideration for manufacturers. To address this Continental has released a new CombineMaster tire, which uses a revised bead construction, called Hexa, which improves both on road performance while reducing soil compaction.
By using a bead core made of a single piece of steel wrapped around the circumference of the tire up to one hundred times, the company said it has created a combine tire that holds its shape, even when run at very low pressures. “Tires with a single wire bead are safer and quicker to fit, hold the rim better and transfer torque more efficiently which reduces slippage,” explained Continental agricultural tire specialist Richard Hutchins.
Most agricultural tires use as many as 10 individual wires to create one bead. However, multiple joins in the bead can cause weaknesses and there is a risk that the tire can detach from the rim, especially at low pressures. “The bead is as important as the rubber and nylon in a tire. Our research showed a more flexible tire with a stronger single bead construction can be run at a lower pressure which helps to reduce soil compaction. Most importantly the tire will grip the rim even at very low pressures. This reduces the risk of the tire slipping off the rim while helping to spread the huge weight of a combine,” said Hutchins.
Continental also said the hexagonal section of its bead is stronger and smoother than the common rectangular design which also makes it better on the road. Hutchins noted: “This is especially important for the front tires which take more weight and torque. Our N.Flex carcass material coupled with the Hexa bead makes the CombineMaster tire safer and more comfortable on the road.”
Hutchins also explained why the incorporation of N.Flex – a heat-treated nylon that sits beneath the rubber to help the tire return to its original shape following impacts and heavy use – improves operator comfort: “Combine tires reach high temperatures during road use. When parked overnight the tires cool to the shape of the parked position creating so called flat spots. When the combine is used again the operator will experience ride disturbance because the tires are not a perfect circle. N.Flex reduces the occurrence of flat spots and provides a more comfortable ride.”